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CHAPTER

All-in-1 / A+ Certification Exm Gde, 6th Ed. / Meyers / 6311-3

7Motherboards

In this chapter, you will learn how to• Explain how motherboards work• Identify the types of motherboards• Explain chipset varieties• Upgrade and install motherboards• Troubleshoot motherboard problems

The motherboard provides the foundation for the personal computer. Every piece of hardware, from the CPU to the lowliest expansion card, directly or indirectly plugs into the motherboard. The motherboard contains the wires—called traces—that make up the different buses of the system. It holds the vast majority of the ports used by the peripherals and it distributes the power from the power supply (Figure 7-1). Without the motherboard, you literally have no PC.

Figure 7-1 Traces visible beneath the CPU socket on a motherboard

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CompTIA A+ Certification All-in-One Exam Guide

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Historical/Conceptual

How Motherboards WorkThree variable and interrelated characteristics define modern motherboards: form fac-tor, chipset, and components. The form factor determines the physical size of the moth-erboard as well as the general location of components and ports. The chipset defines the type of processor and RAM required for the motherboard, and determines to a degree the built-in devices supported by a motherboard, including the expansion slots. Finally, the built-in components determine the core functionality of the system.

Any good tech should be able to make a recommendation to a client about a par-ticular motherboard simply by perusing the specs. Because the motherboard determines function, expansion, and stability for the whole PC, it’s essential that you know your motherboards!

Form FactorsForm factors are industry standardized shapes and layouts that enable motherboards to work with cases and power supplies. A single form factor applies to all three components. All motherboards come in a basic rectangular or square shape, for example, but vary in overall size and the layout of built-in components (Figure 7-2). You need to install a moth-erboard in a case designed to fit it, so the ports and slot openings on the back fit correctly.

The power supply and the motherboard need matching connectors, and different form factors define different connections. Given that the form factor includes the case, mother-board, and power supply—the three parts of the PC most responsible for moving air around inside the PC—the form factor also defines how the air moves around in the case.

Figure 7-2 Typical motherboard



Chapter 7: Motherboards

225To perform motherboard upgrades and provide knowledgeable recommendations

to clients, techs need to know their form factors. The PC industry has adopted—and dropped—a number of form factors over the years with names such as AT, ATX, BTX, and others. Let’s start with the granddaddy of all PC form factors, AT.

AT Form FactorThe AT form factor (Figure 7-3), invented by IBM in the early 1980s, was the predomi-nant form factor for motherboards through the mid-1990s. AT is now obsolete. The AT type of motherboard had a large keyboard plug in the same relative spot on the moth-erboard, and it had a unique, split power socket called P8/P9.

Figure 7-3 AT-style motherboard

The AT motherboard had a few size variations, ranging from large to very large (Fig-ure 7-4). The original AT motherboard was huge, around 12 inches wide by 13 inches deep. PC technology was new and needed lot of space for the various chips needed to run the components of the PC, such as the keyboard.

Figure 7-4 AT motherboard (bottom) and Baby AT motherboard (top)




226The single greatest problem with AT motherboards was the lack of external ports.

When PCs were first invented, the only devices plugged into the average PC were a monitor and a keyboard. That’s what the AT was designed to handle—the only dedi-cated connector on an AT motherboard was the keyboard plug (Figure 7-5).

Figure 7-5 Keyboard connector on the back of an AT motherboard

Over the years, the number of devices plugged into the back of the PC has grown tremendously. Your average PC today has a keyboard, a mouse, a printer, some speak-ers, a monitor, and if your system’s like mine, four to six USB devices connected to it at any given time. These added components created a demand for a new type of form fac-tor, one with more dedicated connectors for more devices. Many attempts were made to create a new standard form factor. Invariably, these new form factors integrated ded-icated connectors for at least the mouse and printer, and many even added connectors for video, sound, and phone lines.

One variation from the AT form factor that enjoyed a degree of success was the slim-line form factor. The first slimline form factor was known as LPX (defined in some sources as low profile extended, although there’s some disagreement). It was replaced by the NLX form factor. (NLX apparently stands for nothing, by the way. It’s just a cool grouping of letters.) The LPX and NLX form factors met the demands of the slimline market by pro-viding a central riser slot to enable the insertion of a special riser card (Figure 7-6). Expan-sion cards then fit into the riser card horizontally. Combining built-in connections with a riser card enabled manufacturers to produce PCs shorter than 4 inches.

Figure 7-6 Riser card on an older motherboard




227The main problem with form factors like LPX and NLX was their inflexibility. Cer-

tainly, no problem occurred with dedicated connections for devices such as mice or printers, but the new form factors also added connectors for devices like video and sound—devices that were prone to obsolescence, making the motherboard useless the moment a new type of video or sound card came into popularity.

EssentialsATX Form FactorThere continued to be a tremendous demand for a new form factor—a form factor that had more standard connectors, but at the same time was flexible enough for possible changes in technology. This demand led to the creation of the ATX form factor in 1995 (Figure 7-7). ATX got off to a slow start, but by around 1998 ATX overtook AT to be-come the most common form factor used today.

Figure 7-7 Early ATX motherboard

CPU in socket CPU fan power External ports RAM

PCI slots

AGP slot

Flash BIOS chip

System clock battery

Southbridge

Front panel connections

DIP switches

EIDE ports Floppy port Northbridge Power connector




228ATX is distinct from AT in the lack of an AT keyboard port, replaced with a rear

panel that has all necessary ports built in. Note the mini-DIN (PS/2) keyboard and mouse ports in Figure 7-8, standard features on almost all ATX boards.

Figure 7-8 ATX ports

PS/2 (mouse)

PS/2 (keyboard)

USB ports Serial portsParallel port

Mini-audio ports (speaker, line in, microphone)

Joystick/MIDI port

The ATX form factor includes many improvements over AT. The position of the power supply enables better air movement. The CPU and RAM are placed to enable easier access. Other improvements, such as placement of RAM closer to the North-bridge and CPU than on AT boards, offer users enhanced performance as well. The shorter the wires, the easier to shield them and make them capable of handling double or quadruple the clock speed of the motherboard. Figure 7-9 shows an AT and an ATX motherboard—note the radical differences in placement of internal connections.

Figure 7-9 AT (left) and ATX (right) motherboards for quick visual comparison

ATX motherboards use a feature called soft power. This means that they can use soft-ware to turn the PC on and off. The physical manifestation of soft power is the power switch. Instead of the thick power cord used in AT systems, an ATX power switch is little more than a pair of small wires leading to the motherboard. We delve into this in more detail in Chapter 8, “Power Supplies.”

The success of ATX has spawned two form factor subtypes for specialty uses. The microATX motherboard (Figure 7-10) floats in at a svelte 9.6 by 9.6 inches or about 30




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percent smaller than standard ATX, yet still uses the standard ATX connections. A micro-ATX motherboard fits into a standard ATX case or in the much smaller microATX cases. Note that not all microATX motherboards have the same physical size. You’ll sometimes see microATX motherboards referred to with the Greek symbol for micro, as in µATX.

In 1999, Intel created a variant of the microATX called the FlexATX. FlexATX moth-erboards have maximum dimensions of just 9 by 7.5 inches, which makes them the smallest motherboards in the ATX standard. Although FlexATX motherboards can use a standard ATX power supply, most FlexATX systems use a special FlexATX-only power supply. This diminutive power supply fits into tight FlexATX cases.

NOTE NOTE You’ll find many techs and Web sites use the term mini-ATX to refer to motherboards smaller than a full ATX board. This is technically incorrect. The specifications for these small boards use only the terms microATX and FlexATX.

Keep in mind that each main type of form factor requires its own case. AT mother-boards go into AT cases, NLX motherboards go into NLX cases, and ATX motherboards go into ATX cases. You cannot replace one form factor with another without purchasing a new case (Figure 7-11). The exception to this rule is that larger form factor ATX cases can handle any smaller-sized form factor motherboards.

Figure 7-10 Micro-ATX




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BTX Form FactorEven though ATX addressed ventilation, faster CPUs and powerful graphics cards create phenomenal amounts of heat, motivating the PC industry to create the “coolest” new form factor used today—the Balanced Technology eXtended (BTX) form factor (Figure 7-12). BTX defines three subtypes: standard BTX, microBTX, and picoBTX, designed to replace ATX, microATX, and FlexATX, respectively.

Figure 7-11 That’s not going to fit!

Figure 7-12 microBTX motherboard




231At first glance, BTX looks like ATX, but notice that the I/O ports and the expansion

slots have switched sides. You can’t put a BTX motherboard in an ATX case! BTX does not change the power connection, so there’s no such thing as a BTX power supply.

NOTE NOTE Many manufacturers sell what they call “BTX power supplies.” These are actually marketing gimmicks. See Chapter 8, “Power Supplies,” for details.

Everything in the BTX standard is designed to improve cooling. BTX cases vent in cool air from the front and warm air out the back. CPUs are moved to the front of the motherboard so they get cool air coming in from the front of the case. BTX defines a special heat sink and fan assembly called the thermal unit. The thermal unit’s fan blows the hot CPU air directly out the back of the case, as opposed to the ATX method of just blowing the air into the case.

The BTX standard is clearly a much cooler option than ATX, but the PC industry tends to take its time when making big changes like moving to a new form factor. As a result, BTX has not yet made much of an impact in the industry, and BTX mother-boards, cases, and thermal units are still fairly rare. BTX will take off to become the next big thing or disappear in a cloud of disinterest—only time will tell.

Proprietary Form FactorsSeveral major PC makers, including Dell and Sony, make motherboards that work only with their cases. These proprietary motherboards enable these companies to create sys-tems that stand out from the generic ones and, not coincidently, push you to get service and upgrades from their authorized dealers. Some of the features you’ll see in proprie-tary systems are riser boards like you see with the NLX form factor—part of a mother-board separate from the main one, but connected by a cable of some sort—and unique power connections. Proprietary motherboards drive techs crazy as replacement parts tend to cost more and are not readily available.

ChipsetEvery motherboard has a chipset. The chipset determines the type of processor the motherboard accepts, the type and capacity of RAM, and what sort of internal and ex-ternal devices the motherboard supports. As you learned in earlier chapters, the chips in a PC’s chipset serve as electronic interfaces through which the CPU, RAM, and input/output devices interact. Chipsets vary in feature, performance, and stability, so they fac-tor hugely in the purchase or recommendation of a particular motherboard. Good techs know their chipsets!

Because the chipset facilitates communication between the CPU and other devices in the system, its component chips are relatively centrally located on the motherboard (Figure 7-13). Most modern chipsets are composed of two primary chips—the North-bridge and the Southbridge.




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The Northbridge chip on Intel-based motherboards helps the CPU work with RAM, as mentioned in earlier chapters. On AMD-based motherboards, the Northbridge pro-vides the communication with the video card, rather than memory, because the mem-ory controller is built into the CPU. Current Northbridge chips do a lot and thus get pretty hot, so they get their own heat sink and fan assembly (Figure 7-14).

Figure 7-13 Northbridge (under the fan) and Southbridge (lower right, labeled VIA)

Figure 7-14 Heat sink and fan on a Northbridge




233The Southbridge handles some expansion devices and mass storage drives, such as

hard drives. Most Southbridge chips don’t need extra cooling, leaving the chip exposed or passively cooled with only a heat sink. This makes the Southbridge a great place to see the manufacturer of the chipset, such as Intel (Figure 7-15).

Figure 7-15 An Intel NH82801 Southbridge chip on a motherboard

Figure 7-16 Super I/O chip on ASUS motherboard

Most motherboards support very old technologies such as floppy drives, infrared connections, parallel ports, and modems. Although supporting these old devices was once part of the Southbridge’s job, hardly any modern chipsets still support these de-vices. Motherboard manufacturers add a third chip called the Super I/O chip to handle these chores. Figure 7-16 shows a typical Super I/O chip.

NOTE NOTE Super I/O chips work with chipsets but are not part of the chipset. Motherboard makers purchase them separately from chipsets.




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There are a limited number of chipset makers. Both AMD and Intel make chipsets, but although they may control the CPU market, they have some serious competition in the chipset market. Two third-party chipset makers, VIA Technologies and NVIDIA Cor-poration, make some very popular chipsets. Motherboard manufacturers incorporate the chipsets into motherboards that match the feature set of the chipset. Some of the companies produce chipsets designed for both Intel and AMD CPUs, whereas others choose one or the other company to support. Chipset companies rise and fall every few years, with one company seeming to hold the hot position for a while until another company comes along to unseat them.

NOTE NOTE Due to the purchase by AMD of chipset (and video card) maker ATI in 2006, the chipset field has the potential to change again. ATI makes a nice line of mobile and desktop chipsets. Backed by AMD’s muscle, the combined companies might give VIA and NVIDIA a run for their money. Only time will tell, but it’s something for informed CompTIA A+ certified techs to watch.

NOTE NOTE In an average year, chipset makers collectively produce around one hundred new chipset models for the PC market.

The system ROM chip provides part of the BIOS for the chipset, but only a bare-bones, generic level of support. The chipset still needs support for the rest of the things it can do. So, how do expansion devices get BIOS? Software drivers, of course, and the same holds true for modern chipsets. You have to load the proper drivers for the spe-cific OS to support all the features of today’s chipsets. Without software drivers, you’ll never create a stable, fully functional PC. All motherboards ship with a CD-ROM disc with drivers, support programs, and extra special goodies such as anti-virus software (Figure 7-17).

Figure 7-17 Driver disc for ASUS motherboard




235Chipset makers don’t always use the terms Northbridge and Southbridge. Chipsets

for AMD-based motherboards tend to use the terms, but Intel-based motherboards prefer to use the terms Memory Controller Hub (MCH) for the Northbridge and I/O Controller Hub (ICH) for the Southbridge. Regardless of the official name, Northbridge and Southbridge are the commonly used terms. Figure 7-18 shows a schematic with typical chipset chores for a VIA K8T900 chipset.

Figure 7-18 Schematic of a modern chipset (courtesy of VIA Technologies)

It would be impossible to provide an inclusive chipset chart here that wouldn’t be obsolete by the time you pick this book up off the shelf at your local tech pub (doesn’t everybody have one of those?), but Table 7-1 gives you an idea of what to look for as you research motherboards for recommendations and purchases.




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237So why do good techs need to know the hot chipsets in detail? The chipset defines

almost every motherboard feature short of the CPU itself. Techs love to discuss chipsets and expect a fellow tech to know the differences between one chipset and another. You also need to be able to recommend a motherboard that suits a client’s needs.

Motherboard ComponentsThe connections and capabilities of a motherboard sometimes differ from that of the chipset the motherboard uses. This disparity happens for a couple of reasons. First, a particular chipset may support eight USB ports, but to keep costs down the manufac-turer might include only four ports. Second, a motherboard maker may choose to in-stall extra features—ones not supported by the chipset—by adding additional chips. A common example is a motherboard that supports FireWire. Other technologies you might find are built-in sound, hard drive RAID controllers, and AMR or CNR slots for modems, network cards, and more.

USB/FireWireMost chipsets support USB and most motherboards come with FireWire as well, but it seems no two motherboards offer the same port arrangement. My motherboard supports eight USB ports and two FireWire ports, for example, but if you look on the back of the motherboard, you’ll only see four USB ports and one FireWire port. So, where are the other ports? Well, this motherboard has special connectors for the other four USB and one FireWire port, and the motherboard comes with the dongles you need to connect them (Figure 7-19). These dongles typically use an extra slot on the back of the case.

Figure 7-19 USB/FireWire dongles

These dongle connectors are standardized, so many cases have built-in front USB/FireWire ports that have dongles attached. This is very handy for USB or FireWire de-vices you might want to plug and unplug frequently, such as a thumb drive or digital camera. You can also buy add-on front USB and FireWire devices that go into a 3.5-inch drive bay, like a floppy drive (Figure 7-20).




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SoundQuite a few motherboards come with onboard sound chips. These sound chips are usu-ally pretty low quality compared to even a lower-end sound card, but onboard sound is cheap and doesn’t take up a slot. These connectors are identical to the ones used on sound cards, so we’ll save more discussion for Chapter 18, “Sound.”

RAIDRAID stands for redundant array of independent devices and is very common on mother-boards. There are many types of RAID, but the RAID on motherboards usually only supports mirroring (the process of using two drives to hold the same data, which is good for safety because if one drive dies, the other still has all the data) or striping (making two drives act as one drive by spreading data across them, which is good for speed). RAID is a very cool but complex topic that’s discussed in detail in Chapter 9, “Hard Drive Technologies.”

AMR/CNRThe U.S. Federal Communications Commission (FCC) must certify any electronic de-vice to ensure that it does not transmit unwanted electronic signals. This process is a bit expensive, so in the very late 1990s Intel came up with a special slot called the audio modem riser (AMR). See Figure 7-21. An AMR slot was designed to take specialized AMR devices (modems, sound cards, and network cards). An AMR device would get one FCC certification and then be used on as many motherboards as the manufac-turer wanted without going through the FCC certification process again. AMR was quickly replaced with the more advanced communications and networking riser (CNR). Many motherboard manufacturers used these slots in the early 2000s, but they’ve lost popularity because most motherboard makers simply use onboard networking and sound.

Figure 7-20 Front USB and FireWire drive bay device




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Figure 7-21 AMR slot

Upgrading and Installing MotherboardsTo most techs, the concept of adding or replacing a motherboard can be extremely in-timidating. It really shouldn’t be; motherboard installation is a common and necessary part of PC repair. It is inexpensive and easy, although it can sometimes be a little te-dious and messy due to the large number of parts involved. This section covers the process of installation and replacement and will show you some of the tricks that make this necessary process easy to handle.

IT TechnicianChoosing the Motherboard and CaseChoosing a motherboard and case, whether new or old, can prove quite a challenge for a tech. You first have to figure out the type of motherboard you want, such as AMD- or Intel-based. Then you need to think about the form factor, which of course influences the type of case you’ll need. Third, how rich in features is the motherboard and how tough is it to configure? You’ve got to read the motherboard manual to find out! Fi-nally, you need to select the case that matches your space needs, budget, and form fac-tor. Let’s look at each step in a little more detail.




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EXAM TIP EXAM TIP Every CompTIA A+ technician should know how to select and install a motherboard appropriate for a client or customer. This is particularly important if you’re studying for the CompTIA A+ 220-604 Depot Technician exam, but less so for those working toward the CompTIA A+ 220-603 Help Desk Technician exam.

First, determine what motherboard you need. What CPU are you using? Will the motherboard work with that CPU? Because most of us buy the CPU and the mother-board at the same time, make the seller guarantee that the CPU will work with the motherboard. If you can, choose a motherboard that works with much higher speeds than the CPU you can afford; that way you can upgrade later. How much RAM do you intend to install? Are extra RAM sockets available for future upgrades?

A number of excellent motherboard manufacturers are available today. Some of the more popular brands are Abit, Asus, Biostar, DFI, Gigabyte, Intel, MSI, and Shuttle. Your supplier may also have some lesser-known but perfectly acceptable brands of motherboards. As long as the supplier has an easy return policy, it’s perfectly fine to try one of these.

Second, make sure you’re getting a form factor that works with your case. Don’t try to put a regular ATX motherboard into a microATX case!

Third, all motherboards come with a technical manual, better known as the moth-erboard book (Figure 7-22). You must have this book! This book is your only source for all of the critical information about the motherboard. If you set up CPU or RAM tim-ings incorrectly in CMOS, for example, and you have a dead PC, where would you find the CMOS clear jumper? Where do you plug in the speaker? Even if you let someone else install the motherboard, insist on the motherboard book; you will need it.

Figure 7-22 Motherboard box and book




241Fourth, pick your case carefully. Cases come in six basic sizes: slimline, desktop,

mini-tower, mid-tower, tower, and cube. Slimline and desktop models generally sit on the desk, beneath the monitor. The various tower cases usually occupy a bit of floor space next to the desk. The mini-tower and mid-tower cases are the most popular choic-es. Make sure you get a case that will fit your motherboard—many microATX and all FlexATX cases are too small for a regular ATX motherboard. Cube cases generally re-quire a specific motherboard, so be prepared to buy both pieces at once. A quick test fit before you buy saves a lot of return trips to the supplier.

Cases come with many different options, but three more common options point to a better case. One option is a removable face (Figure 7-23)—many cheaper cases will screw the face into the metal frame using wood screws. A removable face makes disas-sembly much easier.

Figure 7-23 Removable face

Another option is a detachable motherboard mount. Clearly, the motherboard will have to be attached to the case in some fashion. In better cases, this is handled by a remov-able tray or plate (Figure 7-24). This enables you to attach the motherboard to the case separately, saving you from the chore of sticking your arms into the case to turn screws.

Figure 7-24 Motherboard tray




242The third option, front-mounted ports for USB, FireWire, and headphones, can make

using a PC much easier. Better cases offer these ports, although you can also get add-on components that fit into the increasingly useless floppy drive bay to bring added front connectivity to the PC. Figure 7-25 shows a case with both types of front connectors.

Figure 7-25 Case with both front-mounted ports and an add-on flash memory card reader

Power supplies often come with the case. Watch out for “really good deal” cases, because that invariably points to a cheap or missing power supply. You also need to verify that the power supply has sufficient wattage. This issue is handled in Chapter 8, “Power Supplies.”

Building a RecommendationFamily, friends, and potential clients often solicit the advice of a tech when they’re thinking about upgrading their PC. This solicitation puts you on the spot to make not just any old recommendation, but one that works with the needs and budget of the potential upgrader. To do this successfully, you need to manage expectations and ask the right questions. Let’s take a quick look at how you might do this.

Start by finding out what the upgrader wants to do that compels him or her to up-grade. Write it down! Some of the common motivations for upgrading are to play that hot new game or to take advantage of new technology. What’s the minimum system needed to run tomorrow’s action games? What do you need to make multimedia sing?




243Does the motherboard need to have FireWire and Hi-Speed USB built in to accommo-date digital video and better printers?

Your next line of inquiry should be to find out how much of the current system the upgrader wants to save. Upgrading a motherboard can very quickly turn into a com-plete system rebuild. How old is the case? If it’s an AT case, you pretty much need to look at a full computer replacement, but if it’s a generic ATX case, you can usually save that much. On the other hand, if you want to use front-mounted USB and FireWire ports, then you’ll want a new case as well. You’ll most likely want to replace the CPU, so your first decision is AMD vs. Intel. The former gives you more bang for the buck, but the latter offers peace of mind for non-techs. What about RAM? Do you stick with the SDRAM or DDR SDRAM currently in the PC and go for a lower-end board that supports the older technology, or buy a board that uses DDR2? Do you go for a motherboard that supports AGP—and thus keep the current video card—or go for a PCI Express board that will require a new video card as well?

Once you’ve gathered information on motivation and assessed the current PC of the upgrader, it’s time to get down to business: field trip time! This is a great excuse to get to the computer store and check out the latest motherboards and gadgets. Don’t forget to jot down notes and prices while you’re there! By the end of the field trip, you should have the information to give the upgrader an honest assessment of what an upgrade will entail, at least in monetary terms. Be honest—in other words, don’t just tell the up-grader what you think he or she wants to hear—and you won’t get in trouble!

Installing the MotherboardIf you’re replacing a motherboard, first remove the old motherboard. Begin by remov-ing all the cards. Also remove anything else that might impede removal or installation of the motherboard, such as hard or floppy drives. Keep track of your screws—the best idea is to return the screws to their mounting holes temporarily, at least until you can reinstall the parts. Sometimes even the power supply has to be removed temporarily to enable access to the motherboard. Document the position of the little wires for the speaker, power switch, and reset button in case you need to reinstall them.

EXAM TIP EXAM TIP The CompTIA A+ Essentials exam will test you on the basics of installing a motherboard, so you need to know this section!

Unscrew the motherboard. It will not simply lift out. The motherboard mounts to the case via small connectors called standouts that slide into keyed slots or screw into the bottom of the case (Figure 7-26). Screws then go into the standouts to hold the moth-erboard in place. Be sure to place the standouts properly before installing the new motherboard.

CAUTION CAUTION Watch out for ESD here! Remember that it’s very easy to damage or destroy a CPU and RAM with a little electrostatic discharge. It’s also fairly easy to damage the motherboard with ESD. Wear your anti-static wrist strap!




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A lot of techs install the CPU, CPU fan, and RAM into the motherboard before in-stalling the motherboard into the case. This helps in several ways, especially with a new system. First, you want to make certain that the CPU and RAM work well with the motherboard and with each other—without that, you have no hope of setting up a stable system. Second, installing these components first prevents the phenomenon of flexing the motherboard. Some cases don’t provide quite enough support for the moth-erboard, and pushing in RAM can make the board bend. Third, attaching a CPU fan can be a bear of a task, one that’s considerably easier to do on a table top than within the confines of a case. Finally, on motherboards that require you to set jumpers or switches, it’s much easier to read the tiny information stenciled on the PCB before you add the shadows from the case! If necessary, set any jumpers and switches for the specific CPU according to information from the motherboard manual.

When you insert the new motherboard, do not assume that you will put the screws and standouts in the same place as they were in your old motherboard. When it comes to the placement of screws and standouts, only one rule applies: anywhere it fits. Do not be afraid to be a little tough here! Installing motherboards can be a wiggling, twist-ing, knuckle-scraping process.

CAUTION CAUTION Pay attention to the location of the standouts if you’re swapping a motherboard. If you leave a screw-type standout beneath a spot on the motherboard where you can’t add a screw and then apply power to the motherboard, you run the risk of shorting the motherboard.

Once you get the motherboard mounted in the case with the CPU and RAM prop-erly installed, it’s time to insert the power connections and test it. A POST card can be helpful with the system test because you won’t have to add the speaker, a video card,

Figure 7-26 Standout on a case, ready for the motherboard




245monitor, and keyboard to verify that the system is booting. If you have a POST card, start the system and watch to see if the POST takes place—you should see a number of POST codes before the POST stops. If you don’t have a POST card, install a keyboard, speaker, video card, and monitor. Boot the system and see if the BIOS information shows up on the screen. If it does, you’re probably okay. If it doesn’t, it’s time to refer to the motherboard book to see where a mistake was made.

Wires, Wires, WiresThe last, and often the most frustrating, part of motherboard installation is connecting the LEDs, buttons, and front-mounted ports on the front of the box. These usually in-clude the following:

• Soft power

• Reset button

• Speaker

• Hard drive activity LED

• Power LED

• USB

• FireWire

• Sound

These wires have specific pin connections to the motherboard. Although you can refer to the motherboard book for their location, usually a quick inspection of the motherboard will suffice for an experienced tech (Figure 7-27).

Figure 7-27 Motherboard wire connections labeled on the motherboard

A few rules need to be followed when installing these wires. First, the lights are LEDs, not light bulbs—they have a positive and negative side. If they don’t work one way, turn the connector around and try the other. Second, when in doubt, guess. Incor-rect installation only results in the device not working; it won’t damage the computer. Refer to the motherboard book for the correct installation. The third and last rule is that with the exception of the soft power switch on an ATX system, you do not need any of these wires for the computer to run! Many techs often simply ignore these wires, al-though this would not be something I’d do to any system but my own!




246No hard-and-fast rule exists for determining the function of each wire. Often, the

function of each wire is printed on the connector (Figure 7-28). If not, track each wire to the LED or switch to determine its function.

Figure 7-28 Sample of case wires

Troubleshooting MotherboardsMotherboards fail. Not often, but motherboards and motherboard components can die from many causes: time, dust, cat hair, or simply slight manufacturing defects made worse by the millions of amps of current sluicing through the motherboard traces. In-stalling cards, electrostatic discharge, flexing the motherboard one time too many when swapping out RAM or drives—any of these factors can cause a motherboard to fail. The motherboard is a hard-working, often abused component of the PC! Unfortunately for the common tech, troubleshooting a motherboard problem can be very difficult and time-consuming. Let’s wrap this chapter with a look at symptoms of a failing mother-board, techniques for troubleshooting, and the options you have when you discover a motherboard problem.

EXAM TIP EXAM TIP If you’re studying for the CompTIA A+ 220-604 Depot Technician exam, pay particular attention to the techniques for troubleshooting motherboards.

SymptomsMotherboard failures commonly fall into three types: catastrophic, component, and ethereal. With a catastrophic failure, the PC just won’t boot. This sort of problem hap-pens with brand-new systems due to manufacturing defects—often called a burn-in fail-




247ure—and to any system that gets a shock of electrostatic discharge. Burn-in failure is uncommon, but usually happens in the first 30 days of use. Swap out the motherboard for a replacement and you should be fine. If you accidentally zap your motherboard when inserting a card or moving wires around, be chagrined. Change your daring ways and wear an anti-static wrist strap!

Component failure happens rarely, but appears as flaky connections between a de-vice and motherboard, or as intermittent problems. A hard drive plugged into a faulty controller on the motherboard, for example, might show up in CMOS autodetect, but be inaccessible in Windows. A serial controller that worked fine for months until a big storm took out the external modem hooked to it, but doesn’t work anymore, even with a replacement modem, is another example.

The most difficult of the three types of symptoms to diagnose are those I call ethe-real symptoms. Stuff just doesn’t work all the time. The PC reboots itself. You get blue screens of death in the midst of heavy computing, like right before you smack the vil-lain and rescue the damsel. What can cause such symptoms? If you answered any of the following, you win the prize:

• Faulty component

• Buggy device driver

• Buggy application software

• Slight corruption of the operating system

• Power supply problems

Err…you get the picture.What a nightmare scenario to troubleshoot! The Way of the Tech knows paths

through such perils, though, so let’s turn to troubleshooting techniques now.

TechniquesTo troubleshoot a potential motherboard failure requires time, patience, and organiza-tion. Some problems will certainly be quicker to solve than others. If the hard drive doesn’t work as expected, as in the example above, check the settings on the drive. Try a different drive. Try the same drive with a different motherboard to verify that it’s a good drive. Like every other troubleshooting technique, all you try to do with mother-board testing is to isolate the problem by eliminating potential factors.

This three-part system—check, replace, verify good component—works for the sim-pler and the more complicated motherboard problems. You can even apply the same technique to ethereal-type problems that might be anything, but you should add one more verb: document. Take notes on the individual components tested so you don’t re-peat efforts or waste time. Plus, this can lead to the establishment of patterns. Being able to re-create a system crash by performing certain actions in a specific order can often lead you to the root of the problem. Document your actions. Motherboard testing is time-consuming enough without adding inefficiency!




248

OptionsOnce you determine that the motherboard has problems, you have several options for fixing the three types of failures. If you have a catastrophic failure, you must replace the motherboard. Even if it works somewhat, don’t mess around. The motherboard should provide bedrock stability for the system. If it’s even remotely buggy or problematic, get rid of it!

If you have a component failure, you can often replace the component with an add-on card that will be as good as or better than the failed device. Promise Technologies, for example, makes fine hard drive controller cards that can replace one or both hard drive controllers on the motherboard (Figure 7-29).

Figure 7-29 Promise Technology PCI hard drive controller card

CAUTION CAUTION If you’ve lost components due to ESD or a power surge, then you would most likely be better off replacing the motherboard. The damage you can’t see can definitely sneak up to bite you and create system instability.

If your component failure is more a technology issue rather than physical damage, then you can try upgrading the BIOS on the motherboard. As you’ll recall from Chapter 5 on BIOS, every motherboard comes with a small set of code that enables the CPU to communicate properly with the devices built into the motherboard. You can quite readily upgrade this programming by flashing the BIOS: running a small command-line program to write new BIOS in the Flash ROM chip. Figure 7-30 shows a couple of typi-cal Flash ROMs. Refer back to Chapter 5 for the details on flashing.




249

Flashing the BIOS for a motherboard can fix a lot of system stability problems and provide better implementation of built-in technology. What it cannot do for your sys-tem is improve the hardware. If AMD comes out with a new, improved, lower-voltage Athlon 64, for example, and your motherboard cannot scale down the voltage properly, then you cannot use that CPU—even if it fits in your motherboard’s Socket AM2. No amount of BIOS flashing can change the hardware built into your motherboard.

Finally, if you have an ethereal, ghost-in-the-machine type of problem that you have finally determined to be motherboard related, you have only a couple of options for fixing the problem. You can flash the BIOS in a desperate attempt to correct what-ever it is, which sometimes does work and is less expensive than the other option. Or, you can replace the motherboard.

Beyond A+

Shuttle Form FactorIn the early 2000s, Shuttle started making a very interesting line of tiny cube-shaped PCs called XPCs that became an overnight sensation and continue to be popular today (Figure 7-31). These boxes use a tiny, proprietary form factor motherboard, called Shut-tle Form Factor, installed in a proprietary case with a proprietary power supply. Origi-nally, these systems were sold barebones, meaning they came with only a motherboard,

Figure 7-30 AMI and Award Flash ROM chips




250case and power supply. You had to supply a CPU, RAM, video card, keyboard, mouse, and monitor. Shuttle now produces a full line of computers.

Figure 7-31 Shuttle XPC (photo courtesy of Shuttle Computer Group, Inc.)

Many companies followed Shuttle’s lead and started making cube or cube-like small cases. You’ll hear these cases commonly referred to as small form factor (SFF), but there’s no industry-wide standard. Most SFF cases accommodate microATX and Flex-ATX motherboards.

Mini-ITXIf you really want to get small, check out Mini-ITX (Figure 7-32). Developed by VIA Technologies in 2001, mini-ITX has a maximum size of only 17 centimeters by 17 cen-timeters! These tiny systems only use the VIA C3 family of CPUs, so if you want to get really picky, mini-ITX is a proprietary computer system, not really a form factor. Mini-ITX also has its own tiny power supply standard. The low power requirements don’t require a fan on some systems. The VIA C3 CPUS aren’t as powerful as the latest offer-ings from Intel and AMD, but they’re great for specialized jobs such as home theater systems or manufacturing.




251

NOTE NOTE Watch out for all the pretty colors on today’s motherboards! To catch the consumer’s eye, a lot of motherboard manufacturers have started making wildly colorful motherboard components. There is no universally accepted standard for connection colors on the inside of a motherboard.

Chapter Review Questions 1. Which of the following form factors dominates the PC industry?

A. AT

B. ATX

C. BTX

D. CTX

2. Which of the following form factors offers the best cooling?

A. AT

B. ATX

C. BTX

D. CTX

Figure 7-32 Mini-ITX motherboard




252 3. On Intel-based motherboards, which chip enables the CPU to interact with

RAM?

A. Memorybridge

B. Northbridge

C. Southbridge

D. Super I/O

4. On modern motherboards, which chip most commonly supports floppy drives and infrared ports?

A. Memorybridge

B. Northbridge

C. Southbridge

D. Super I/O

5. Brian bought a new motherboard that advertised support for eight USB ports. When he pulled the motherboard out of the box, however, he found that it only had four USB ports! What’s likely the issue here?

A. The extra four USB ports will connect to the front of the case or via a dongle to an expansion slot.

B. The extra four USB ports require an add-on expansion card.

C. The FireWire port will have a splitter that makes it four USB ports.

D. The motherboard chipset might support eight USB ports, but the manufacturer only included four ports.

6. Which of the following chips enables an Athlon 64 to use dual-channel DDR RAM?

A. ATI 200 Express

B. NVIDIA nForce 570 SLI Intel

C. NVIDIA nForce 590 SLI AMD

D. None of the above

7. Martin bought a new motherboard to replace his older ATX motherboard. As he left the shop, the tech on duty called after him, “Check your standouts!” What could the tech have meant?

A. Standouts are the connectors on the motherboard for the front panel buttons, like the on/off switch and reset button.

B. Standouts are the metal edges on some cases that aren’t rolled.

C. Standouts are the metal connectors that attach the motherboard to the case.

D. Standouts are the dongles that enable a motherboard to support more than four USB ports.




253 8. Amanda bought a new system that, right in the middle of an important

presentation, gave her a blue screen of death. Now her system won’t boot at all, not even to CMOS. After extensive troubleshooting, she determined that the motherboard was at fault and replaced it. Now the system runs fine. What was the most likely cause of the problem?

A. Burn-in failure

B. Electro-static discharge

C. Component failure

D. Power supply failure

9. Solon has a very buggy computer that keeps locking up at odd moments and rebooting spontaneously. He suspects the motherboard. How should he test it?

A. Check settings and verify good components.

B. Verify good components and document all testing.

C. Replace the motherboard first to see if the problems disappear.

D. Check settings, verify good components, replace components, and document all testing.

10. Steve has been tasked to upgrade ten systems at his office. The systems currently have microATX motherboards with 512 MB of DDR RAM and Athlon XP CPUs. Primary objective: Upgrade ten systems.Optional objectives: Use the current cases and use the current RAM. Proposed solution: Purchase ten microATX motherboards with NVIDIA nForce 570 SLI Intel chipsets and ten Pentium D CPUs. The proposed solution:

A. Accomplishes only the primary objective.

B. Accomplishes the primary objective and one of the optional objectives.

C. Accomplishes the primary objective and both of the optional objectives.

D. Accomplishes neither the primary nor the optional objectives.

Answers

1. B. Almost all modern motherboards follow the ATX form factor.

2. C. Although not widely adopted by the industry, BTX motherboards offer superior cooling to AT or ATX systems.

3. B. The Northbridge enables the communication between the CPU and RAM.

4. D. The Super I/O chip handles older technologies such as floppy drives and infrared ports.




254 5. A. The extra four USB ports most likely connect to the front of the case or via

a dongle to an expansion slot.

6. D. Athlon 64 CPUs have a memory controller built in; thus, none of the chips listed handles memory access for the CPU.

7. C. Standouts are the metal connectors that attach the motherboard to the case.

8. A. Although all the answers are plausible, the best answer here is that her system suffered burn-in failure.

9. D. Solon needs to check settings, verify good components, replace components, and document all testing.

10. B. The motherboards would fit just fine in the cases because the switch from AMD to Intel CPUs has nothing to do with the form factor of the motherboards. Steve slipped up, however, because the chipset on the new motherboards requires DDR2 rather than DDR RAM.


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